SCREENING, ISOLATION AND CHARACTERIZATION OF HEAT STRESS TOLERANT TRICHODERMA ISOLATES: SUSTAINABLE ALTERNATIVE TO CLIMATE CHANGE

Abstract

To provide food security with quality crops for exponentially growing population brought intense pressure on the limited land and natural resources among developing countries. Abiotic stresses such as continuously rising temperature as consequences of global warming is adding pressure to existing problems by adversely affecting crop productivity through physiological changes in plants. Hence there is need of qualitatively potential vegetable crops that can withstand changing environmental conditions such as Okra (Abelmoschus spp.) holding high level of nutrients along with economic importance. But requirement of high temperature and humidity for its cultivation make the plant prone to several phytopathogens that ultimately leads to severe qualitative and quantitative losses depending upon the plant growth stage getting affected. Due to the unenviable problems of chemical fertilizers, biocontrol agents were applied as auxiliary treatments either single or in combination that possess fewer consequences on the environment. But due to increasing environmental and soil temperature, activities of these formulations are getting hindered. Therefore, there is an urgent requirement to procure high temperature stress tolerant strains along with antagonistic and plant growth promoting abilities. In the current study, we mainly focused on isolation of high temperature tolerant Trichoderma harzianum (BHU P4) strain with antagonistic abilities against fungal pathogen Sclerotium rolfsii causing collar rot disease. The strain was also studied for plant growth promoting attributes in okra plant which resulted in increased fresh weight, dry weight, chlorophyll content and nutrient content in comparison to control and pathogen challenged plants. This study was associated with an improvement in the level of total phenol, SOD, PO and PAL enzymes in order to regulate the host defense mechanism against its confrontation with S. rolfsii.